Answer this question truthfully
### Question: What causes Pulmonary hypertension?
### Response: The right side of the heart pumps blood through the lungs, where it can receive oxygen. When the small arteries (blood vessels) of the lung become narrowed, they cannot carry as much blood. When this happens, pressure builds up. This is called pulmonary hypertension. The heart needs to work harder to force the blood through the vessels against this pressure. Over time, the right side of the heart may become enlarged. At some point, not enough blood flows to the lungs to pick up oxygen and symptoms begin. At this point, heart failure that involves the right side of the heart is present. This is called cor pulmonale.
Pumonary hypertension may be caused by:
Any condition that causes chronic low oxygen levels in the blood Autoimmune diseases that damage the lungs, such as scleroderma and rheumatoid arthritis Certain birth defects of the heart Certain diet medications Congestive heart failure History of a blood clot in the lung (pulmonary embolism) HIV infection Lung or heart valve disease Obstructive sleep apnea
In many cases the cause is unknown, in which case the condition is known as idiopathic pulmonary arterial hypertension (IPAH). IPAH is rare. It affects more women than men.
If it is caused by a known medicine or medical condition, it is called secondary pulmonary hypertension.